Nail.



No. 644,286. Patented Feb. 27, I900. J. T. EYSTER.

NAIL.

(Application filed Apr. 18, 1 899.) (No Model.)

Ni'rE STATES ATENT Felon,

NAIL.

SPECIFICATION forming part of Letters Patent No. 644,286, dated February 27, 1900.

Application filed April 18, 1899. Serial No. 713,483. (No model.)

To all whom it may concern:

Be it known that I, JOHN THOMAS EYSTER, a citizen of the United States, residing at Eagleville, county of Modoc, State of California, have invented an Improvement in Nails; and I hereby declare the following to be a full, clear, and exact description ofthe same.

My invention relates to an improvement in nails.

It consists, essentially,in forming the upper part of the shank cylindrical, the lower part being flattened and twisted into a spiral having a rounded tapering point, the opposite angles of which are sharpened. to a cutting edge. The head of the nail is preferably made hemispherical.

Referring to the accompanying drawings, Figure 1 is a view of the nail. Fig. 2 is a section on line 3 y of Fig. 1.

The object of the invention is to provide a means for securely locking nails of all descriptions when they have been driven and such a formation of the entering-point as will insure the cutting of the fibers of the wood to form a channel into which the spiral of the nail passes and to lessen the danger of splitting the wood by the driving of such a nail.

The shank A of the nail is made, as here shown, preferably cylindrical for a certain length below the head, and preferably that portion of the nail which passes through the part to be held may be made of this form. Below this the material is gradually flattened to a comparatively-thin plate, which is afterward twisted to form a spiral, as shown at A-. The front edge E of the spiral is made thin to out its way, and the rear edge D is thickened for strength. The lower end of this spiral is curved to form a rounded point, as shown, and the edges of this point are beveled, as shown at C, so as to cut through the wood when the nail is driven, and one of these edges merges into the thin front edge E of the spiral.

The head B has its upper surface preferably made hemispherical, so that the blows of the hammer in striking it will be more di rectly conveyed in the line of the nail and will not tend to twist or break the head if the blow be struck a little to one side or not quite in line.

The rounded and beveled end of the nail serves to carry the nail more directly in a straight line than if a sharpened point were used, since the latter might be diverted by a knot or hard place in the wood, while the rounded beveled point would cut its way through the obstruction like a chisel.

As the nail is driven it turns by reason of the spiral formation which follows the cut made by the point, and when the cylindrical shank, which is of larger diameter than the thickness of the spiral, enters the wood it will bind and lock itself inthe channel already cut, because of its greater diameter, and will thus hold firmly in place.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-

An improved nail having the upper part of the shank cylindrical and the lower part flattened'and twisted into spiral form, the front edge of the spiral being beveled to an edge and the rear edge square and without bevel, to give increased strength at that point, and said nail having a rounded point with its edges beveled and with one of the edges merging into the beveled front edge of the spiralbody.

In witness whereof I have hereunto set my hand.

JOHN THOMAS EYSTER. Witnesses:

W. A. FENWIOK, T. H. J OHNSTONE. 

